This study was conducted to: 1) determine if water level
fluctuations in the Niagara River affect water temperatures in the Niagara
River, U.S. tributaries of the Niagara River, and Lewiston Reservoir, and, if
so, 2) describe the nature and extent of the temperature effects and their
potential influence on the behavior and survival of fish.

The study area extended from the head of the Niagara River
to its mouth and was divided into six zones based on physical habitat
characteristics (water depth, water velocity, substrate, presence of
vegetation) that influence the distribution of fish species:

·Zone 1 - Buckhorn Marsh and tributaries of the
Niagara River

·Zone 2 -Deeper portions of the upper Niagara River (the channel)

·Zone 3 -Shallower portions of the upper Niagara River (shoals)

·Zone 4 -The lower Niagara River between Niagara Falls and the tailrace of the
Niagara Power Project (the gorge)

·Zone 5 -The lower Niagara River downstream of the tailrace of the Niagara Power
Project

·Zone 6 -Lewiston Reservoir

The first objective was addressed by comparing portions of
the six zones that were influenced by water level changes in the Niagara River
with appropriate reference conditions to determine if there were differences in
maximum and minimum water temperatures that occur daily and seasonally, the
periodicity of temperature changes, and hourly rate of change in water
temperature.The second objective was
addressed by describing the temperatures in zones affected by water level
changes in the Niagara River and assessing the potential for those temperature
changes to affect the behavior and survival of fish from 18 species considered
representative of their communities, listed as threatened or endangered
species, or known to be the target of important recreational fisheries.

Water level and water temperature data were collected from
temporary gauges during 2002 and 2003.During 2002:

·Water temperature was recorded every 15-minutes
from April to November 2002 at 21 sites in the upper and lower Niagara River,
Woods Creek, Buckhorn Marsh, Burnt Ship Creek, Big Sixmile Creek, Gun Creek,
Spicer Creek, and around Strawberry Island;

·Water level was recorded every 15-minutes from
March to November 2002 at 10 temporary gauge locations in the upper and lower
Niagara River, Woods Creek, Buckhorn Marsh, and Burnt Ship Creek;

·Water level was recorded at eight permanent
water level gauges in the upper and lower Niagara River and Lewiston Reservoir.

During 2003, water temperature data were collected from
February or March, to November in:

·The channel of the upper Niagara River upstream
of the mouth of Spicer Creek, downstream of the mouth of Woods Creek, just
upstream of the Niagara Power Project intakes, and near the Peace Bridge;

·The lower Niagara River upstream of the Niagara
Power Project tailrace, in the tailrace, just downstream of the tailrace, at
the Lewiston Landing, Artpark, Joseph Davis State Park, and the Youngstown
Yacht Club.

Water level was recorded hourly during 2003 from February
or March, to November in:

·The lower Niagara River upstream of the Niagara
Power Project tailrace, Artpark, Lewiston Landing, Joseph Davis State Park, and
near the Youngstown Yacht Club.

Data from permanent water level gauges in the upper
Niagara River and Lewiston Reservoir were also collected in 2003 as in
2002.Water level data from Lewiston Reservoir,
Material Dock, Slater’s Point, NYPA Intake, Tonawanda Island, Huntley, Black
Creek, Frenchman’s Creek, Fort Erie, and Port Weller (Lake Ontario) were used
in this analysis.Temporary water level
gauge data were plotted in relation to permanent gauge data in the upper
Niagara River, Lake Ontario or Lewiston Reservoir, as appropriate.

Hourly air temperature, relative humidity, barometric
pressure, solar radiation, precipitation, and wind direction and speed data
were collected at two local, National Oceanic and Atmospheric Administration
(NOAA) weather stations (Niagara Falls International Airport and Buffalo
Niagara International Airport) from March 2002 to November 2002 and from
February 2003 to November 2003.

Water level fluctuations did not affect the normal range
in seasonal and diurnal temperatures and did not affect the hourly rate of
temperature change anywhere in Zones 2, 4, 5, and 6.However, water level fluctuations did cause
more rapid changes in water temperature at several gauges in Zones 1 and 3.
Zone 1 water temperature changes ranging from –6.5 to +2.3 ºC/hour occurred at
16 of 39 gauges, mostly in the lower reaches of tributaries near the confluence
with the Niagara River.In Zone 3, water
temperature changes ranging from -4.1 to +4.4 ºC/hour occurred at two of seven
locations, both at or immediately downstream of tributary mouths.The areal extent of the hourly temperature
changes was not evaluated.

The potential for water temperature changes of the
magnitude that occurred during 2002 and 2003 to affect the behavior and
survival of fishes in the study area appears relatively small.They are adapted to the range of daily and
seasonal water temperatures that occur in the study area.The rate of change in water temperature at all
locations was not large enough to potentially reduce survival rates because of
cold shock or heat shock or to potentially cause avoidance behavior in most
species and life stages.More frequent
water temperature changes may displace fish in limited portions of the study
area but the potential is considered relatively small.

D°CAT hourly
change in air temperature in degrees Centigrade (positive or negative)

D°CWThourly
change in water temperature in degrees Centigrade (positive or negative)

DTchange
in temperature

DWLhourly
change in water level in feet (positive or negative)

CCelsius,
Centigrade

cfscubic
feet per second

FFahrenheit

fpsfeet
per second

ftfeet

MWmegawatt

psipounds
per square inch

USLSDU.S.
Lake Survey Datum 1935

Environmental

DOdissolved
oxygen

EAVemergent
aquatic vegetation

LILTlower
incipient lethal temperature

SAVsubmerged
aquatic vegetation

UILTupper
incipient lethal temperature

Miscellaneous

LPGPLewiston
Pump Generating Plant

NFIANiagara Falls International
Airport

NYPANew York Power Authority

OPGOntario Power Generation

RMNPPRobert
Moses Niagara Power Project

1.0INTRODUCTION

The New York Power Authority (NYPA) is engaged in the
relicensing of the Niagara Power Project (NPP) in Lewiston, Niagara County, New
York.The present operating license of
the plant expires in August 2007.As
part of its preparation for the relicensing of the Niagara Project, NYPA is
developing information related to the ecological, engineering, recreational,
cultural, and socioeconomic aspects of the Project.

The 1,880 megawatt (MW) (firm capacity) NPP is one of the
largest non-federal hydroelectric facilities in North America.The Project was licensed to the Power
Authority of the State of New York (now the New York Power Authority) in
1957.Construction of the Project began
in 1958, and electricity was first produced in 1961.

The Project has several components.Twin intakes are located approximately 2.6
miles above Niagara Falls, in a portion of the river referred to as the
Chippawa-Grass Island Pool.Water levels
within the pool are managed using the International Niagara Control Structure,
a partial dam across the river.Water
levels in the pool are raised using this structure, and drawn into the
intakes.The intake water is routed
around the Falls via two large low-head conduits to a 1.8-billion-gallon
forebay, lying on an east-west axis about 4 miles downstream of the Falls. The
forebay is located on the east bank of the Niagara River.At the west end of the forebay, between the
forebay itself and the river, is the Robert Moses Niagara Power Plant (RMNPP),
NYPA’s main generating plant at Niagara.This plant has 13 turbines that generate electricity from water stored
in the forebay.Head is approximately
300 feet. At the east end of the forebay
is the Lewiston Pump Generating Plant (LPGP).Under non-peak-usage conditions (i.e., at night and on weekends), water
is pumped from the forebay via the plant’s 12 pumps into the 22-billion-gallon
Lewiston Reservoir, which lies east of the plant.During peak usage conditions (i.e., daytime
Monday through Friday), the pumps are reversed for use as generators, and water
is allowed to flow back through the plant, producing electricity.The forebay therefore serves as headwater for
the RMNPP and tailwater from the LPGP.South of the forebay is a switchyard, which serves as the electrical
interface between the Project and its service area.Water levels in the forebay, which are
directly influenced by power generation, in turn influence water levels in the
Chippawa-Grass Island Pool.

For purposes of generating electricity using the Niagara
River, two seasons are recognized:tourist season and non-tourist season.By the 1950 Niagara River Water Diversion Treaty, at least 100,000 cfs
must be allowed to flow over Niagara Falls during daytime hours in the tourist
season (April 1 – October 31), and at least 50,000 cfs at all other times.Canada and the United States are entitled by
international treaty to produce hydroelectric power using the remaining flows,
sharing equally.

Water level fluctuations in the Chippawa-Grass Island
Poolare limited by an International
Joint Commission (IJC) directive to 1.5 feet per day unless conditions
triggering special provisions occur.Water
level fluctuations in both the upper and lower Niagara River are caused by a
number of factors other than operation of the Niagara Power Project.These include wind, natural flow and ice
conditions, regional and long-term precipitation patterns that affect lake
levels, control of Niagara Falls flow for scenic purposes, operation of power
plants on the Canadian side of the river, and the backwater effect from Lake
Ontario.Water level fluctuations in the
upper Niagara River from all causes are normally less than 1.5 feet per day.

During tourist season, water level fluctuations in the
lower Niagara River (upstream of the RMNPP tailrace) normally amount to 10-12
feet per day.Water level fluctuations
downstream of the RMNPP tailrace are much smaller.The average daily water level fluctuation 1.4
miles downstream of the RMNPP tailrace, during the 2002 tourist season, was
approximately 1.5 feet.

Operation of the NPP can result in water level
fluctuations in the Lewiston Reservoir of 3-18 feet per day, and as much as 36
feet per week.

1.1Objectives

The objectives of this study were to: 1) determine if
water level fluctuations in the Niagara River affect water temperatures in the
Niagara River, U.S. tributaries of the Niagara River, and Lewiston Reservoir,
and, if so, 2) describe the nature and extent of the temperature effects and
their potential influence on the behavior and survival of fish.Rather than consider all fish species
occurring in the Niagara River, 18 species (focus species) considered representative
of the fish community in the investigation area, listed as threatened or
endangered species, or known to be the target of important recreational
fisheries were selected (Table 1.1-1).These are the same fish species considered in
an earlier report that assessed the effect of water level fluctuations on
habitat (Stantec et al. 2005), however, rainbow
(steelhead) trout was also included in the present report.

Water level and flow fluctuations in both the upper and
lower Niagara River are caused by a number of factors. Natural factors include
flow surges from Lake Erie caused by wind, ice conditions, and regional and
long-term precipitation patterns that affect lake levels. Manmade factors include
boat wakes, regulation of Niagara Falls flows for scenic purposes, operation of
hydroelectric plants on the Canadian side of the river, and operation of the
NPP.The sources and extent of water
level fluctuations in the Niagara River and its tributaries were examined in
detail as part of the FERC relicensing effort (URS et
al. 2005a).Because changes in water
level are the result of the complex interplay between natural and multiple
anthropogenic causes, it is difficult to distinguish the extent of water level
change attributable to U.S./Canadian power generation versus other
sources.Therefore, while temperature
effects related to water level fluctuations may be identified, it is difficult
to fully quantify what proportion of these effects can be attributed to
U.S./Canadian power generation.

The investigation area for this analysis included the
Niagara River from the Peace Bridge to its mouth on Lake Ontario, it’s U.S.
tributaries, and the Lewiston Reservoir (Figure 1.2-1).The period of analysis considered is from
March 1st to November 30th, 2002
and 2003, however, the period from April 1st to October 31st
is a focus of particular interest.During this latter period, referred to as the ‘tourist season’, regular
water level fluctuations occur between day and night due to treaty obligations
requiring minimum flows of 100,000 cfs over Niagara Falls during daylight
hours.Water level fluctuation in the
upper Niagara River from all causes, including power production by both U.S.
and Canadian plants and natural factors, normally amounts to less than 1.5 feet
per day as measured at Material Dock, the official monitoring gauge. The 1.5
foot daily water level fluctuation is allowed by the 1993 Directive of the
International Niagara Board of Control (INBC). The portion of upper-river water
level changes attributable to power production is the result of varying
withdrawals of water byNYPA and Ontario
Power Generation (OPG). It was found that regulation of the Chippawa-Grass
Island Pool water levels has a more pronounced effect during the tourist than
the non-tourist period. The reason for this is that during non-tourist hours
the pool is maintained at a lower water level so that the scenic Falls flow
remains close to 50,000 cfs.To
compensate for water levels lower than the long-term mean specified by the 1993
Directive, the pool elevation is higher during tourist hours.

Tributary streams considered in this investigation are Big
Sixmile Creek, Spicer Creek, Gun Creek, and the Burnt Ship Creek/Woods
Creek/Buckhorn Marsh complex on Grand Island; and Tonawanda Creek, Ellicott
Creek and Cayuga Creek on the mainland.Sections of these tributary streams are exposed to water level
fluctuations in the Chippawa-Grass Island Pool.Gill Creek is a mainland tributary that receives flow augmentation from
Lewiston Reservoir during summer months, and may therefore also be subject to
temperature effects.

In addition to these drainages, Fish Creek, a tributary to
the lower Niagara River is also examined.However, there is no potential for direct effects on water temperature
on Fish Creek from water level fluctuations in the Niagara River.Fish Creek is exposed to groundwater seepage
from Lewiston Reservoir at both locations where temperatures were monitored in
2003 (URS et al. 2005b).This creek enters the lower Niagara River via
a high gradient cascade and the limited area of channel exposed to water level
fluctuations in the lower Niagara River does not provide suitable fish
habitat.

1.3Causes
of Water Temperature Fluctuations in the Investigation Area

There are three causes of water temperature fluctuation in
the Niagara River and its tributaries.These include: seasonal variations in meteorological factors; diurnal
(daily) variations in meteorological factors; and mixing of different water
bodies at different temperatures.These
three sources of temperature fluctuation vary in terms of the rate at which
temperature changes occur, and the extent of area affected.

Temperature changes due to mixing can be associated with
large rainfall events, natural changes in river elevation (e.g., due to storm
surges, ice flows, etc.), changes in river elevation due to U.S./Canadian power
generation, and possibly other sources such as boat wakes.The degree of temperature change is most
pronounced when the difference in temperature between the water bodies being
mixed is greatest.Changes in water
temperature resulting from mixing tend to occur much more rapidly than diurnal
fluctuations.For example, if
fluctuations in Niagara River water levels cause river water to flow into and
recede from tributaries, and tributary water is much warmer or cooler than the river
water, water temperatures in the zone of mixing can change dramatically in a
short period of time.Similarly, if
shallow water areas of the Niagara River are at different temperatures from the
main channel, fluctuations in water level could lead to relatively rapid
changes in water temperature at those shallow water locations.In contrast to seasonal and diurnal
temperature fluctuations, which are widespread, large rapid changes in water
temperature due to mixing are limited to the area in which the mixing
occurs.It is not unusual for a
tributary stream to be a different temperature than its associated larger
river, and the mixing of tributary and river water at the mouth of a tributary
is a natural occurrence.

The influence of natural factors as well as manmade
factors on Niagara River water level fluctuations should be considered when
examining the effect of U.S./Canadian power generation on water temperature
conditions.In general, water level
fluctuations in the upper Niagara River are normally less than 1.5 feet per day
(URS et al. 2005a).However, most of the largest daily water level fluctuations observed
upstream of the Chippawa-Grass Island Pool were caused by natural factors.URS et al. (2005a)
investigated the causes of large daily water level fluctuations along the
Niagara River at eleven gauges.Of the
ten highest recorded fluctuations for each of the nine upper river gauges
(Material Dock, Slater’s Point, NYPA Intake, LaSalle, Black Creek, Tonawanda
Island, Huntley, Frenchman’s Creek, and Fort Erie), 84% were attributed to
rapid flow surges at Fort Erie.The
remaining 16% of the large fluctuations, which were primarily for gauges in the
Chippawa-Grass Island Pool (i.e., Material Dock, Slater’s Point, NYPA Intake,
LaSalle) were conservatively attributed to regulation but may also be partially
caused by localized environmental conditions such as wind and local
runoff.

In the lower Niagara River at the Ashland Avenue gauge
(upstream of the RMNPP tailrace), water levels are typically affected most by
the change in treaty flow requirements that occurs between the daytime (100,000
cfs) and nighttime (50,000 cfs) flows during the tourist season. Daily fluctuations
normally range between 10 and 12 feet.However nine of the ten largest daily water level fluctuations which
were between 17 and 23 feet, were caused by high flow surges from Lake Erie (URS et al. 2005a).

Water levels downstream of the RMNPP tailrace are a
function of Lake Ontario level, discharge from RMNPP and Canadian plants, and
flow rate over Niagara Falls.In
general, water levels downstream of the RMNPP tailrace fluctuate much less than
the levels between the Falls and tailrace since the river is wider downstream
of the tailrace, and is influenced by the water level of Lake Ontario.In general, the change in the Falls flow and
power generation produce relatively predictable daily water level fluctuations.
The average daily water level
fluctuation during the 2002 tourist season at the gauge located 1.4 miles
downstream of the RMNPP tailrace was approximately 1.5 feet with a range of 1.1
to 2.1 feet.

This investigation examines the effect of water level
fluctuations on water temperatures in the Niagara River by evaluating the effect
of water level fluctuations on the hourly rate of change in water temperature
and on seasonal and diurnal temperature fluctuations.

A combination of methods was used to determine if changes
in water level associated with joint U.S. and Canadian hydropower operations
and treaty flow requirements led to changes in water temperature of sufficient
magnitude to affect the behavior and survival of fish.If temperature variations attributable to
water level fluctuations were identified at a given location, the magnitude of
these fluctuations were evaluated against tolerance thresholds for the life
history stages of focus species likely to be present at the time the variations
occur.The likely presence of focus fish
species was determined based on field surveys of habitat suitability and fish
presence determined during various studies conducted as part of the Niagara
Power Project FERC relicensing process (Stantec et al.
2005, Stantec et al. 2004URS et
al. 2002, EI 2001 and 2002,
KA 2002).

The remainder of this section is organized as follows:

·Section 2.1:Data collection methods

·Section 2.2:Analysis zones defined for the investigation

·Section 2.3:Data analysis methods

1.1Water
Level, Water Temperature, and Meteorological Data Collection

Temperature and water level data were collected for the
purpose of this investigation in 2002 and 2003 from a number of temporary and
existing permanent gauge stations in the investigation area.A total of 39 temporary water temperature
gauges were placed throughout the investigation area to collect water
temperature data at 15-minute time increments between April 1st and
November 30th of 2002, and March 1st to November 30th of
2003 (some locations began recording later in 2003).A total of 24 temporary water level gauges
were placed to collect water elevation data over the same time increments and
periods.The temporary water level
gauges complemented data gathered from 10 existing permanent water level gauges
present in the investigation area.Some
temporary water level gauges were also configured to gather temperature data,
providing a total of 64 gauge locations with available temperature data for
analysis.Data from one of these gauge
locations (TM-23) was later found to be unreliable and was removed from the
analysis.In addition to the water level
and water temperature data, NOAA meteorological data collected from two nearby
locations was used to describe other environmental conditions that affect water
temperatures.All data was subjected to
rigorous QA/QC review to ensure the analysis was based on reliable and accurate
information.Water level, water
temperature and air temperature data were compiled as hourly averages and
plotted by month and location to establish the existing patterns of seasonal
and diurnal (daily) temperature fluctuation throughout the investigation
period.The temperature and water level
data set used in this investigation includes significant storm events that
occurred in 2002 and 2003.

Water surface elevations were collected on a 15-minute
time step at 24 temporary locations during 2003 using In-Situ miniTROLL,
Professional Model (30 psi) gauges.These gauges also recorded water temperature on the same time step.Continuous water temperature data were
collected from additional sites using Onset Computer Corporation’s Optic
StowAway Temp gauges.The continuous
temperature data were collected using the In-Situ logger, the Onset logger, or
both at a total of 39 locations in the Niagara River, Lewiston Reservoir and
U.S. tributaries.Performance
specifications (range, resolution and accuracy) for the monitoring equipment
used in this study, and data quality assurance and quality control procedures
are described in Appendix A.

Both water level and water temperature data were collected
from the temporary data gauges in 2002 and 2003.In 2002, these data were collected from the
following locations (Figure 2.1-1) and time increments:

·Water temperature collected at 15-minute
increments from April to November 2002 at a total of 21 sites in the upper and
lower Niagara River, Woods Creek, Buckhorn Marsh, Burnt Ship Creek, Big Sixmile
Creek, Gun Creek, Spicer Creek, and around Strawberry Island;

·Water level data collected at 15-minute
intervals from March to November 2002 at a total of 10 temporary gauge
locations in the upper and lower Niagara River, Woods Creek, Buckhorn Marsh,
and Burnt Ship Creek;

·Hourly water level data collected at a total of
8 permanent water level gauge locations in the upper and lower Niagara River
and Lewiston Reservoir in 2002.

In 2003, water temperature
data were collected from February or March to November from the following
locations (Figure 2.1-2) and time increments with the
number of sites in each area in parentheses:

·The mainstem of the upper Niagara River upstream
of the mouth of Spicer Creek (1), downstream of the mouth of Woods Creek (1),
just upstream of the intakes (1), and near Peace Bridge (1);

·The mainstem of the lower Niagara River upstream
of the tailrace (1), in the tailrace (1), just downstream of the tailrace (1),
at the Lewiston Landing (1), Artpark (1), Joseph Davis State Park (1), and the
Youngstown Yacht Club (1).

Water level data were collected hourly in 2003 from
February or March to November in the following areas (Figure
2.1-2), with the number of sites in each area in parentheses:

·The mainstem of the lower Niagara River upstream
of the tailraces (1), at Artpark (1), at Lewiston Landing (1), at Joseph Davis
State Park (1), and near the Youngstown Yacht Club (1).

For tributary sites, water level and water temperature
data were collected within and upstream of the areas influenced by water level
fluctuations in the Niagara River.This
provided a limited set of reference locations for tributary water temperatures.

Data from permanent water level gauges in the upper Niagara
River and Lewiston Reservoir (Figure 2.1-1) were also
collected in 2003 as in 2002.Water
level data from Lewiston Reservoir, Material Dock, Slater’s Point, NYPA Intake,
Tonawanda Island, Huntley, Black Creek, Frenchman’s Creek, Fort Erie, and Port
Weller (Lake Ontario) were used in this analysis.Generally, temporary water level gauge data
were plotted in relation to permanent gauge data in the upper Niagara River,
Lake Ontario or Lewiston Reservoir, as appropriate.

Hourly air temperature, relative humidity, barometric
pressure, solar radiation, precipitation, and wind direction and speed data
collected at two local, NOAA weather stations from March 2002 to November 2002
and from February 2003 to November 2003.The exact weather stations from which data were obtained are shown in Figure 2.1-3.These
stations include the Niagara Falls International Airport and Buffalo Niagara
International Airport.

Charts of water level, water temperature, and air
temperature data were developed for grouped locations in support of this
analysis.The charts are presented in Appendix B of this report.A table of contents provides a listing of the
charts developed, including the specific location, and gauge data shown on each
chart.

All temperature gauges are identified with a unique alpha
numeric code.Gauges collecting
temperature data in 2002 begin with TM-, and are numbered 01 through 25 (e.g.,
TM-01)Gauges specifically collecting
temperature data in 2003 have location codes beginning with T and specific to
the area being surveyed (e.g., TUNR-01: Upper Niagara River location-01).Gauges collecting water level data in 2002
have two letter alpha numeric codes beginning with “S” (e.g., SD-01).Gauges collecting water level data in 2003
have three letter location specific identifiers not beginning with T (e.g.,
SMC-01, Big Sixmile Creek location –01).Note that these water level gauges also collected temperature data used
in this investigation.Gauge location
and type descriptions are in Table 2.1.1.

Throughout this report, all environmental data (water
elevations, water temperatures, air temperatures) are in Eastern Standard Time,
whereas descriptions of, and references to, the 1950 Niagara River Water
Diversion Treaty are in Eastern Daylight Savings Time.

1.2Analysis
Zones

For the purpose of this analysis,
the investigation area was divided into 6 distinct analysis zones.These analysis zones were developed based on
physical habitat characteristics, and the extent of influence by water level
fluctuations.The analysis zones are
defined as follows:

The methods of data analysis used in this investigation
were developed in part based on the findings of previous investigations of
water level fluctuations in the Niagara River and its tributaries.The methodology used to analyze temperature
effects on focus species was conducted to answer the following questions:

1.Are observed
water temperature fluctuations in the investigation area within the range of
natural seasonal and diurnal variability?

2.Do
rapid changes in water temperature due to mixing of water bodies occur
regularly?

3.Do
these rapid changes in water temperature potentially influence the behavior or
survival of fish?

As implied, this evaluation involved three primary
steps.The first step was to determine
ifwater level fluctuations affect the
normal range of seasonal and diurnal temperature fluctuations.The second step was to determine if the
timing of water level fluctuations appear to be correlated with the timing of
water temperature changes at specific times and locations, with effects
occurring in the form of rapid, temporary temperature fluctuations.If such a relationship was identified, the third
step was to determine if the extent of the identified temperature effect
exceeds behavioral or survival thresholds for life history stages of focus
species at the affected locations and times.These three steps are described in the following sections.

Using the data collected as described in Section
2.1, the relationship between water level fluctuations and water
temperature was examined, and the results were used to infer the effects of
U.S./Canadian power generation on water temperatures.This approach was sequential and used one or
more of the following analytical methods:

First (visual assessment), graphs of the average hourly
water levels, water temperatures, and air temperatures were created and a
visual assessment of the graphs was used to examine the relationship between
water level fluctuations and water temperatures and water temperature
changes.The visual assessment was used
to determine the locations and times in which water temperatures appeared to be
and appeared not to be affected by water level fluctuations.Second, a correlation analysis (correlation
analysis) was used to determine the relationships between water levels, water
temperatures, and the meteorological factors described in Section
2.4 at those locations (and during those times) that water temperatures
appeared to be and appeared not to be affected by water level fluctuations as
identified during the visual assessment.Third, the seasonal and diurnal patterns (seasonal and diurnal patterns)
in the hourly change in water temperature in degrees Centigrade (positive or
negative) (D°CWT)
were studied at locations affected by water level fluctuations in the Niagara
River in relation to reference locations (independent of water level
fluctuations in the Niagara River).This
included a qualitative evaluation of seasonal and diurnal temperature
fluctuation patterns between reference locations not affected by water level
fluctuations, and locations that may be subject to water level
fluctuations.This consists of two
components:1) determination of normal
patterns of seasonal and diurnal temperature fluctuation based on reference
locations, and; 2) comparison of annual patterns D°CWT between
reference and potentially affected locations.An example graph of annual D°CWT at a reference location is shown in Figure 2.3.1-1.Fourth, (frequency distribution of hourly D°CWT) the frequency
distributions of D°CWT
values by hour of day at locations that may be affected by water level
fluctuations in the Niagara River were compared to those locations that may not
be affected by water level fluctuations in the Niagara River.Fifth, the frequency distributions of hourly
change in water level (DWL) values in feet by hour of day (frequency
distribution of hourly DWL) at locations that may be affected by water level fluctuations in
the Niagara River were compared to those locations not affected by water level
fluctuations in the Niagara River.

The fourth and fifth methods above rely on frequency
distribution boxplots of D°CWT and DWL, respectively.Frequency distributions used in this analysis
show standard boxplots of hourly temperature change values over the period of analysis
by hour of day.An example standard
boxplot is shown in Figure 2.3.1-2.Each standard boxplot consists of a center
line (the median, or 50th percentile) splitting a rectangle defining
the 25th to 75th percentile of values.In other words, 25 percent of the values in a
given plot are above those represented by the range of the box, and 25 percent
are below.The whiskers extend to the
last value within 1.5 times the height of the box (1.5 times the range of 25th
to 75th percentile values), and equal approximately the range of the
1st to the 99th percentile of values.Outlier values, represented by an ‘x’, occur less than one time in one hundred
values in a normally distributed data set, and extreme values, which are not
shown, occur so rarely that they are outside the predicted normal range of the
population of values (Helsel and Hirsch 2002).In contrast to the graphs of annual patterns
in D°CWT,
the frequency distribution boxplots do not show the most extreme values.Extreme events are excluded from this
analysis because they occur so rarely they are unlikely to be caused by human
activities.Water level fluctuations
follow a generally consistent daily pattern.The rarity of outlier and extreme events suggests they are unlikely to
be caused by water level fluctuations due to U.S./Canadian power
generation.Outlier and extreme events
occur at a comparable frequency to large natural changes in river elevation and
are consistent with the likely degree of effect. (Causes of natural changes in
river elevation are described in Section 1.3.)

As mentioned, water level fluctuations in both the upper
and lower Niagara River are caused by a number of factors. Natural factors
include flow surges from Lake Erie, wind, ice conditions, and regional and
long-term precipitation patterns that affect lake levels, while manmade factors
include boat wakes, regulation of Niagara Falls flows for scenic purposes,
operation of hydroelectric power plants on the Canadian side of the river, and
operation of the Niagara Power Project.The influence of these factors on water levels is interrelated and
dynamic. Because the water level in the Niagara River at any location at any
time is a complex function of natural and manmade factors, distinguishing the
exact amount of water level fluctuation attributable to each factor is
difficult.Because rapid changes in
water level at the Fort Erie gauge are due to environmental factors on Lake Erie
(primarily wind events, see Section 1.3), the effects
analysis attempted to distinguish between water temperature effects in the
upper Niagara River caused by U.S./Canadian power generation from those caused
by environmental factors on Lake Erie.Therefore, the effects analysis was based on those hourly temperature
change values that occurred between the 99th and 1st
percentiles.For the lower Niagara
River, where water level fluctuations are less susceptible to environmental
factors, the outlier values were included in the analysis.This approach to determine the effects of
U.S./Canadian power generation on water temperatures in the upper and lower
Niagara River was considered conservative as it is not possible to separate all
other factors that contribute to changes in water levels such as small wind
effects, boat waves and local environmental conditions.Throughout the remainder of this report,
temperature effects in the upper Niagara River based on frequency distribution boxplots
are presented as normal values (i.e., those that occur between the 99th
and 1st percentiles) in ±ºC/hour, and outlier values (±ºC/hour) are
presented only in the figures in Appendix C for
illustrative purposes.For the lower
Niagara River, the analysis of temperature effects was based on both normal and
outlier values in the frequency distribution boxplots.

Different combinations of these five methods were used to
evaluate the effect of U.S./Canadian power generation in each analysis
zone.The analytical approach,
rationale, and selection of analytical methods used in each analysis zone are
described below.

Seasonal and diurnal patterns, frequency distribution of
hourly D°CWT, and frequency
distribution of hourly DWL were used to evaluate the relationship between water
temperature and water level fluctuations in Analysis Zone 1.This approach relies on locations in
tributaries that are known to be independent of water level fluctuations in the
upper Niagara River to provide reference patterns for normal temperature
variation.

The following temperature gauge locations were used to
identify reference patterns:

·SMC-01 (Big Sixmile Creek), 2003 data

·CC-03 (Cayuga Creek), 2003 data

These locations are upstream of the influence of Niagara
River water levels (URS et al. 2005c).There were daily water level fluctuations of
small magnitude (~0.2 feet/day) observed at CC-03, however these fluctuations
don’t show the same daily patterns as observed downstream (URS and Gomez and Sullivan 2005).The fluctuations at CC-03 were likely the
result of a SPDES permitted discharge upstream (Redland Quarry).The Redland Quarry, an operating limestone
mine in the Cayuga Creek watershed with a reported maximum depth of 140 feet
below ground surface (approximately El. 484 feet).It is located approximately 7,500 feet
southeast of the Lewiston Reservoir.Groundwater is extracted from sumps in the mine and discharged to a
tributary of Cayuga Creek.The
extraction and discharge of groundwater at the mine is regulated by SPDES
permit #NY0025267.The mine is permitted
to discharge a maximum of 432,000 gallons of water per day (300 gallons per
minute or 0.67 cfs) to Cayuga Creek (URS et al. 2003).Cayuga Creek has an estimated annual median
flow of 10.7 cfs upstream of the Bergholtz Creek confluence (URS et al. 2005c).Temperature data from these locations were used to establish reference
patterns of seasonal and diurnal temperature variability, annual distribution
of D°CWT
values, and the frequency distribution of hourly D°CWT values.Reference and non-reference gauge locations
in Analysis Zone 1, and analytical methods used in this analysis are listed in Table 2.3.1.1-1.The
pattern and magnitude of daily water level fluctuations at GN-Tonawanda (in the
Tonawanda Channel) are similar to those at GO-Black_Creek (in the Chippawa
Channel).For simplicity, the
GN-Tonawanda data were used to examine the effect of water level fluctuations
on water temperatures in Big Sixmile Creek because the GN-Tonawanda data were
used in the analysis of other upper Niagara River tributaries.

Collectively, the distinct patterns of diurnal temperature
variation, annual patterns of D°CWT, the frequency distribution of hourly D°CWT,
and the frequency distribution of hourly DWL are used to identify
patterns of water temperature changes associated with water level
fluctuations.For the purpose of this
investigation, locations with patterns of water temperature fluctuation that
are routinely dissimilar from patterns present at reference areas (i.e., they
have a high frequency of unusual hourly temperature change values) are
considered to be affected by water level fluctuations.

1.3.1.2Analysis Zone 2:Upper Niagara River – Main Channel

Seasonal and diurnal patterns and frequency distribution
of hourly D°CWT
were used to evaluate the relationship between water temperature and water
level fluctuations in Analysis Zone 2, the main channel of the upper Niagara
River.The following gauge was identified
as a reference location for Niagara River main channel temperature conditions:

·TUNR-03, upper Niagara River at Squaw Island,
2003

This gauge is the furthest upstream on the Niagara River
of all temperature sampling locations.TUNR-03 was placed approximately 1.2 miles downstream of the Peace
Bridge.While this location may be
influenced by water level fluctuations related to U.S./Canadian power
generation at times, there is limited potential for temperature effects at this
mainstem location for the following reasons:

·TUNR-03 is located near the uppermost extent of
the influence of power generation on Niagara River water levels (URS et al. 2005a)

·The volume of flow at this location in a
‘typical’ year ranges from 160,000 to over 250,000 cfs (Stantec
et al. 2005)

Based on these factors, temperature conditions at location
TUNR-03 are determined predominantly by the temperature of surface waters
flowing out of Lake Erie and are considered to be independent of water level
fluctuations in the Niagara River.Reference and non-reference locations in analysis Zone 2, and analytical
methods used in this analysis are listed in Table 2.3.1.2-1.

Seasonal and diurnal patterns and frequency distribution
of hourly D°CWT
were used to evaluate the relationship between water temperature and water
level fluctuations in Analysis Zone 3, the shallow water areas of the upper
Niagara River and immediately downstream of tributaries draining to the river.
Temperature patterns at location TUNR-03 are used as reference patterns for
Analysis Zone 3, with the caveat that this may lead to overestimation of
temperature effects at these locations.Temperature effects may be overestimated because these shallow water
areas may have different conditions than the main river channel reference
gauge.Reference and non-reference gauge
locations in Analysis Zone 3, and analytical methods used in this analysis are
listed in Table 2.3.1.3-1.

Seasonal and diurnal patterns, frequency distribution of hourly
D°CWT, and frequency
distribution of hourly DWL were used to evaluate the relationship between water
temperature and water level fluctuations in Analysis Zone 4, the lower Niagara
River between the falls and the RMNPP tailrace.There is no ideal reference location for this analysis zone, therefore,
temperature conditions are compared to those in the upper river above the falls
to determine iftemperature effects are
occurring.Reference and non-reference
gauge locations in Analysis Zone 4, and analytical methods used in this
analysis are listed in Table 2.3.1.4-1.The extent of available temperature data in
this analysis zone is limited.Therefore, the strength of conclusions based on the lines of evidence
applied is relatively weak in comparison to Analysis Zones 2 and 3.

Seasonal and diurnal patterns, frequency distribution of
hourly D°CWT, and frequency
distribution of hourly DWL were used to evaluate the relationship between water
temperature and water level fluctuations in Analysis Zone 5, the lower Niagara
River below the tailrace.In addition,
water temperatures above and at the tailrace were qualitatively compared with
Lewiston Reservoir temperatures.Temperature conditions in this section of the lower river are compared
to those in the upper Niagara River above the falls to determine if temperature
effects due to water level fluctuations may be occurring.Reference and non-reference gauge locations
in this analysis zone, and analytical methods used in this analysis are listed
in Table 2.3.1.5-1.

1.3.1.6Analysis Zone 6:Lewiston Reservoir

Seasonal and diurnal patterns and frequency distribution
of hourly D°CWTwere used to
evaluate the relationship between water temperature and water level
fluctuations in Analysis Zone 6, Lewiston Reservoir.The reservoir is subject to regular large
changes in water level due to project operations.Temperature conditions in the Lewiston
Reservoir are compared to those in its source body, the upper Niagara
River.Gauge locations evaluated in
Analysis Zone 6 are listed in Table 2.3.1.6.-1.

1.3.2Focus
Species Occurrence by Analysis Zone

The focus species identified in Section 1.1
are not uniformly distributed in the Niagara River and its tributaries, and
several species are limited to specific areas within the investigation
area.To aid in identifying potential
behavior and survival effects, the distribution of focus species within the
previously defined analysis zones was identified based on presence/absence and
creel surveys conducted as part of the Niagara Project FERC relicensing process
(Stantec et al. 2005, URS et
al. 2002, EI 2001 and 2002, KA 2002).Species documented in an analysis zone where suitable spawning habitat
does not occur, spawning has not been documented, or juveniles and adults have
not been documented at appropriate times of year to be indicative in spawning
activity are marked with an asterisk *.Focus species are distributed by Analysis Zone as follows:

Analysis Zone 1:Buckhorn
Marsh and Niagara River Tributaries

·Bluntnose minnow (Pimephales notatus)

·Brown bullhead (Ameiurus nebulosus)

·Emerald shiner (Notropis atherinoides)

·Greater redhorse (Moxostoma valenciennesi)*

·Largemouth bass (Micropterus salmoides)

·Northern pike (Esox lucius)

·Rock bass (Ambloplites
rupestris)

·Smallmouth bass (Micropterus dolomieui)

·White sucker (Catostomus commersoni)

·Yellow perch (Perca flavescens)

Analysis Zone
2: Upper Niagara River - Main Channel

·Bluntnose minnow

·Brown bullhead

·Emerald shiner

·Greater redhorse

·Lake sturgeon (Acipenser fulvescens)

·Lake trout (Salvelinus namaycush)

·Largemouth bass

·Muskellunge (Esox masquinongy)

·Northern pike

·Rainbow trout (Oncorhynchus mykiss)

·Rainbow smelt (Osmerus mordax)

·Rock bass

·Smallmouth bass

·Walleye (Sander vitreus)

·White sucker

·Yellow perch

Analysis Zone 3:Upper Niagara River - Shallow Water Areas Off of Main Channel and
Immediately downstream of Tributaries

·Bluntnose minnow

·Brown bullhead

·Emerald shiner

·Greater redhorse*

·Largemouth bass

·Muskellunge

·Northern pike

·Rainbow smelt

·Rock bass

·Smallmouth bass

·White sucker

·Yellow perch

Analysis Zones 4 and 5:Lower
Niagara River

·American eel (Anguilla rostrata)*

·Bluntnose minnow

·Brown bullhead*

·Chinook salmon (Oncorhynchus tshawytscha)

·Emerald shiner

·Greater redhorse

·Lake sturgeon

·Lake trout

·Largemouth bass

·Muskellunge

·Northern pike

·Rainbow smelt

·Rainbow trout

·Rock bass

·Smallmouth bass

·Walleye

·White sucker

·Yellow perch

Analysis Zone 6: Lewiston
Reservoir

·Emerald shiner

·Northern pike

·Rock bass

·Smallmouth bass

·White sucker

·Yellow perch

1.4Assessment
of Potential Behavioral and Survival Effects on Focus Fish Species

The distribution information in Section
2.3.2 identifies the focus species likely to occur in each analysis
zone.To determine if a temperature
fluctuation at a given location is of sufficient magnitude to cause potential
behavioral or survival effects, the magnitude of the temperature fluctuation
was compared to literature derived temperature tolerance thresholds for life
history stages likely to be present at the time the fluctuations occurred.Four categories of temperature tolerance
thresholds are examined for each focus species at four different life history
stages:

·Egg/embryo:Cold shock and heat shock

·Larvae/fry:Cold shock, heat shock; lower avoidance, upper avoidance

·Juvenile:Cold shock, heat shock; lower avoidance, upper avoidance

·Adult:Cold shock, heat shock; lower avoidance, upper avoidance

Cold shock and heat shock are survival effects.Theyrefer to positive and negative changes in water temperature sufficient
to cause direct mortality, or incapacitation sufficient to greatly increase the
likelihood of mortality (i.e., inability to avoid predators, or to avoid being
carried into unfavorable habitats).Lower avoidance and upper avoidance describe behavioral tolerance
thresholds referring to temperature effects that cause sufficient discomfort to
fish such that they avoid the affected area.While avoidance behavior does not cause direct mortality, it can
indirectly affect survival.For example,
adult fish may abandon nests, leading to loss of egg clutches; some species may
delay spawning; or adult and juvenile fish may abandon otherwise suitable
habitats and be forced to expend energy competing for new cover, resting and
feeding areas.Collectively, these
effects can lead to a survival disadvantage (Schneider
et al. 2002, Hokanson 1977, McCullough 1999, Wydowski and
Whitney 2003, Hubbs and Bailey 1938, Summerfelt 1975, Becker 1983,
Coble 1975).Minor rapid temperature fluctuations (i.e., below defined tolerance
thresholds) may also cause physiological and behavioral stress on focus
species, but the extent of these effects are not well documented.Because water level related fluctuations in
water temperature tend to occur daily, nest building species may avoid building
nests in areas affected by water temperature fluctuations.

Temperature tolerance thresholds for each focus species
and life history stage are presented in Tables 2.4-1 through
2.4-4.These thresholds are derived
from available literature as cited.For
the purpose of this analysis, the following effects thresholds are defined:

·No identified behavioral or survival
effects: water level related temperature fluctuations may or may not
occur, if they do occur they do not exceed behavioral or survivaltolerance thresholds for any focus species in
the analysis zone.

·Potential behavioral effect: Water
level related temperature fluctuationsoccur, and they exceed lower or upper avoidance thresholds at greater
than 1 per 100 event frequency during non-spawning and rearing periods.

·Likely survival effect: Water
level related temperature fluctuations occur, and they exceed cold shock or
heat shock thresholds at greater than 1 per 100 event frequency during any
period.

The exceedence frequency referred to in these effects
criteria is considered to be greater than 1 per 100 events if the ‘whiskers’ of
the standard boxplots of D°CWT values exceed any temperature tolerance
threshold for any species in the analysis zone.Outlier values, represented by an ‘x’
on the boxplots, occur less than 1 in 100 times in a normally distributed
population of events (Helsel and Hirsch 2002).

1.Identification of patterns in D°CWT at
locations affected by water level fluctuations in the Niagara River in relation
to reference locations (independent of water level fluctuations in the Niagara
River)

2.Frequency distributions of D°CWT values by
hour of day at locations that are affected by and not affected by water level
fluctuations in the Niagara River

3.Frequency distributions of DWL values by hour of day
at locations that are affected by and not affected by water level fluctuations
in the Niagara River

1.Identification of patterns in D°CWT at
locations affected by water level fluctuations in the Niagara River in relation
to reference locations (independent of water level fluctuations in the Niagara
River)

2.Frequency distributions of D°CWT values by
hour of day at locations that are affected by and not affected by water level
fluctuations in the Niagara River

3.Frequency distributions of DWL values by hour of day
at locations that are affected by and not affected by water level fluctuations in
the Niagara River

1.Identification of patterns in D°CWT at
locations affected by water level fluctuations in the Niagara River in relation
to reference locations (independent of water level fluctuations in the Niagara
River)

2.Frequency distributions of D°CWT values by
hour of day at locations that are affected by and not affected by water level
fluctuations in the Niagara River

3.Frequency distributions of DWL values by hour of day
at locations that are affected by and not affected by water level fluctuations
in the Niagara River

1.Identification of patterns in D°CWT at
locations affected by water level fluctuations in the Niagara River in relation
to reference locations (independent of water level fluctuations in the Niagara
River)

2.Frequency distributions of D°CWT values by
hour of day at locations that are affected by and not affected by water level
fluctuations in the Niagara River

3.Frequency distributions of DWL values by hour of day
at locations that are affected by and not affected by water level fluctuations
in the Niagara River

1.Identification of patterns in D°CWT at
locations affected by water level fluctuations in the Niagara River in relation
to reference locations (independent of water level fluctuations in the Niagara
River)

2.Frequency distributions of D°CWT values by
hour of day at locations that are affected by and not affected by water level
fluctuations in the Niagara River

3.Frequency distributions of DWL values by hour of day
at locations that are affected by and not affected by water level fluctuations in
the Niagara River

1.Identification
of patterns in D°CWT
at locations affected by water level fluctuations in the Niagara River in
relation to reference locations (independent of water level fluctuations in the
Niagara River)

2.Frequency
distributions of D°CWT
values by hour of day at locations that are affected by and not affected by
water level fluctuations in the Niagara River

1Acclimation
Temperature: Temperature that organism (embryo, larvae, juvenile, or adult) is
acclimated to (acclimation temperatures, if available, are preceded by the @
symbol).

2Delta
Threshold: Change in temperature that produces either avoidance behavior or 50%
mortality

3Cold
Shock: Rapid decrease in temperature documented to cause 50% mortality.Values are given as the negative change of
temperature in ºC the fish or embryos were suddenly subjected to (first value)
and the acclimation temperature in ºC (example: -10@18).Values for the highest and lowest acclimation
temperatures tested are usually given.

4Heat
Shock: Rapid increase in temperature documented to cause 50% mortality.Values are given as the positive change of
temperature in ºC the fish or embryos were suddenly subjected to (first value)
and the acclimation temperature in ºC (example: 10@18).Values for the highest and lowest acclimation
temperatures tested are usually given.

5Lower Avoidance: Rapid decrease in temperature
documented to cause avoidance behavior. A single number indicates that
lifestage has been documented to avoid water of that absolute temperature.

6Upper
Avoidance: Rapid increase in temperature documented to cause avoidance
behavior. A single number indicates that lifestage has been documented to avoid
water of that absolute temperature.

1Acclimation Temperature: Temperature that organism
(embryo, larvae, juvenile, or adult) is acclimated to (acclimation
temperatures, if available, are preceded by the @ symbol).

2Lower
Incipient Lethal Temperature: The lower temperature value beyond which 50% of
the population can no longer survive.Values are given as a lower temperature in ºC the fish or embryos were
suddenly subjected to (first value) and the acclimation temperature in ºC
(example: 6@18).Values for the highest
and lowest acclimation temperatures tested are usually given.

3Upper
Incipient Lethal Temperature: The upper temperature value beyond which 50% of
the population can no longer survive.Values are given as a higher temperature in ºC the fish or embryos were
suddenly subjected to (first value) and the acclimation temperature in ºC
(example: 32@18).Values for the highest
and lowest acclimation temperatures tested are usually given.